Modeling of Corporate Default Risk with Considering Latent Factors

, M.Sc. Thesis Sharif University of Technology Kheiri, Alireza (Author) ; Zamani, Shiva (Supervisor)

Abstract

Credit risk is one important type of various types of financial risks that banks and financial institutions are exposed to it. Therefore credit risk management for banks and other financial institutions that finance corporations and individuals, has special importance. To make decision about financing clients of the bank and managing credit risk, it is essential to measure credit risk of these clients. In recent decades there are many efforts to measure credit risk and therefore various models have been created for assessing it. In this research, we study the effects of Macroeconomic, firm specific and latent variables on clients default risk, in the context of reduced-form models. The...

Design, Manufacturing and Dynamic Modeling of a Coaxial VTOL Micro UAV, Based on Center of Gravity Steering

, M.Sc. Thesis Sharif University of Technology Kheiri, Mohammad Javad (Author) ; Zohoor, Hassan (Supervisor)

Abstract

In recent years, the area of research on micro flying robots has been developed due to the development in micro manufacturing technologies. Due to extra advantages of these flying robots, they are implemented in military and civilian missions such as identifying, espionage, aerial relays, traffic surveillance, rescue, aid, etc. Ability to fly in specified areas, without human injuries, low manufacturing and energy costs, easy and fast implementation, Easy Maintenance, etc, which are some advantages of these robots. We can control these robots manually by remote controllers (RC) or by Auto guidance systems. On the other hand, these robots are used in research laboratories for testing new...

Sharp edge gust effects on aeroelastic behavior of a flexible wing with high aspect ratio

, Article 43rd AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV, 10 January 2005 through 13 January 2005 ; 2005 , Pages 14279-14293 Haddadpour, H ; Shams, Sh ; Kheiri, M ; Sharif University of Technology

2005

Abstract

The subject of the present paper is the investigation of the sharp edged gust effects on the aeroelastic behavior of a flexible wing. It is important to determine the response of the wing to the atmospheric turbulences during normal flight. So, linear modal analysis technique and linear quasi-steady aerodynamic are used for structural modeling and aerodynamic loading, respectively. Also, Lagrange method is used to obtain the system of equations of motion. Using the normal modes of free vibration, structural and aerodynamic matrices can be constructed. Then the aeroelastic instability of the system is determined using p method. Kussner function is used to model the sharp gust effects on the...

A finite-volume-based lattice-Boltzmann method to simulate buoyant flow

, Article 43rd AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV, 10 January 2005 through 13 January 2005 ; 2005 , Pages 2675-2684 Darbandi, M ; Niavarani Kheiri, A ; Schneider, G. E ; Sharif University of Technology

American Institute of Aeronautics and Astronautics Inc 2005

Abstract

Despite great advancement in the lattice Boltzmann method and its application in fluid flow problems, there are still major restrictions in treating either the solution domains with complex boundaries or buoyant flow problems. The past experience shows that the heat equation is a source for instabilities which jeopardizes the stable solution of the lattice Boltzmann method in solving fluid flow problems with heat transfer. The instabilities Increase with increasing buoyant force strength. In this work, we suggest a new approach to overcome the restrictions through implementing the advantages of finite volume method in LBM. In this regard, the lattice Boltzznann equation is incorporated with...

Parallelization of the Lattice Boltzmann model in simulating buoyancy-driven convection heat transfer

, Article 2004 ASME International Mechanical Engineering Congress and Exposition, IMECE, Anaheim, CA, 13 November 2004 through 19 November 2004 ; Volume 375, Issue 1 , 2004 , Pages 305-312 ; 02725673 (ISSN) Niavarani Kheiri, A ; Darbandi, M ; Schneider, G. E ; Sharif University of Technology

American Society of Mechanical Engineers (ASME) 2004

Abstract

The main objective of the current work is to utilize Lattice Boltzmann Method (LBM) for simulating buoyancy-driven flow considering the hybrid thermal lattice Boltzmann equation (HTLBE). After deriving the required formulations, they are validated against a wide range of Rayleigh numbers in buoyancy-driven square cavity problem. The performance of the method is investigated on parallel machines using Message Passing Interface (MPI) library and implementing domain decomposition technique to solve problems with large order of computations. The achieved results show that the code is highly efficient to solve large scale problems with excellent speedup. Copyright © 2004 by ASME

Design and Development of an Image-based Multivariate Control Chart

, M.Sc. Thesis Sharif University of Technology Kazemi Kheiri, Setareh (Author) ; Akhavan Niaki, Taghi (Supervisor)

Abstract

Today we live in an era of continuous technology improvement which results in huge changes in different areas of diverse industries. Among the most recent systems for monitoring and quality control which benefits from high speed, are machine vision systems. The output of these systems, are digital images that can be used for monitoring instead of the original products. Unfortunately due to the computational complexity of data extracted from the digital images, traditional methods lose their efficiency. Therefore, in this thesis, a method is proposed to design a model for the monitoring and control of image-based processes, which uses classification methods, that are capable of classifying...

Bending-torsional flutter of a cantilevered pipe conveying fluid with an inclined terminal nozzle

, Article Journal of Sound and Vibration ; Volume 332, Issue 12 , 2013 , Pages 3002-3014 ; 0022460X (ISSN) Firouz Abadi, R. D ; Askarian, A. R ; Kheiri, M ; Sharif University of Technology

2013

Abstract

Stability analysis of a horizontal cantilevered pipe conveying fluid with an inclined terminal nozzle is considered in this paper. The pipe is modelled as a cantilevered Euler-Bernoulli beam, and the flow-induced inertia, Coriolis and centrifugal forces along the pipe as well as the follower force induced by the jet-flow are taken into account. The governing equations of the coupled bending-torsional vibrations of the pipe are obtained using extended Hamilton's principle and are then discretized via the Galerkin method. The resulting eigenvalue problem is then solved, and several cases are examined to determine the effect of nozzle inclination angle, nozzle aspect ratio, mass ratio and...

An analytical method in computational aeroelasticity based on Wagner function

, Article 25th Congress of the International Council of the Aeronautical Sciences 2006, Hamburg, 3 September 2006 through 8 September 2006 ; Volume 3 , 2006 , Pages 1808-1814 Shams, Sh ; Haddadpour, H ; Sadr Lahidjani, M. H ; Kheiri, M ; Sharif University of Technology

Curran Associates Inc 2006

Abstract

This paper presents an analytical method in computational aeroelasticity for an airfoil considering two degrees of freedom (heaving and pitching) based on the Wagner integral function. In the obtained aeroelastic equations of motion, there are some integral parts that give an integro-differential system of equations. Using appropriate approximation for the Wagner function, a new form of equations can be obtained by derivation from mentioned equations. These equations are in the form of ordinary differential equations. Using the obtained equations, the flutter speed is predicted for a given airfoil and the results are compared with the results of other investigators. Also, the dynamic...

A robust, resilience multi-criteria decision-making with risk approach: a case study for renewable energy location

, Article Environmental Science and Pollution Research ; Volume 30, Issue 15 , 2023 , Pages 43267-43278 ; 09441344 (ISSN) Lotfi, R ; Gharehbaghi, A ; Mehrjardi, M. S ; Kheiri, K ; Ali, S. S ; Sharif University of Technology

Springer Science and Business Media Deutschland GmbH 2023

Abstract

Regarding hard situations like war, the increasing cost of extraction and exploration of fossil fuels make governments move toward green and clear renewable energy (RE). As a result, we propose a novel multi-criteria decision-making (MCDM) method for RE location (REL) for the first time. This model suggests a Robust, Resilience MCDM with Risk approach (RRMCDMR) for REL. We propose a risk approach by adding a risk function in MCDM. A robust convex approach is used to tackle the uncertainty of the model for the real world. We compare the RRMCDMR problem in a wind farm location in Iran with different risk coefficient functions. As defined, Khaf, Nehbandan, and Esfarayan are in locations one to...

Reduce Contra Rotating Propeller (CRP)Noise Level By Improving Design Specifications

, M.Sc. Thesis Sharif University of Technology Kheiri, Ehsan (Author) ; Abbaspour, Madjid (Supervisor) ; Shafii, Mohammad Behshad (Co-Supervisor)

Abstract

One of the biggest problems in improving the performance of submersible propellers is the acoustic standard in conventional propellers. Recently, new solutions in propellers geometry have been used to reduce non-cavitation noise. Designing CRP licenses is one of these methods. This research includes numerical analysis. Numerical analysis in this research solves RANS equations of flow and extraction of hydrodynamic parameters and impeller noise in Ansys software. The results of numerical hydrodynamic solution are validated by laboratory results.DTMB 4119 three-blade propeller is used for hydrodynamic and hydroacoustic validation. The solution of Lighthill equations by FW-H method is...

Evaluation of UiO-66 metal organic framework as an effective sorbent for curcumin's overdose

, Article Applied Organometallic Chemistry ; Volume 32, Issue 4 , 2018 ; 02682605 (ISSN) Molavi, H ; Zamani, M ; Aghajanzadeh, M ; Kheiri Manjili, H ; Danafar, H ; Shojaei, A ; Sharif University of Technology

John Wiley and Sons Ltd 2018

Abstract

Metal organic frameworks (MOFs) UiO-66 (UiO stands for University of Oslo) and NH2-UiO-66 were prepared and characterized as sorbent (antidotal agents) for curcumin (CUR) adsorption. The structure of products were characterized by X-ray powder diffraction (XRD), Field emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), Attenuated Total Reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and N2 adsorption–desorption measurements. FESEM showed NH2-UiO-66 displayed symmetrical crystals with triangular base pyramid morphology, with the particle size around 100 nm and uniform size distribution. Adsorption capacities of CUR/MOFs with different mass ratios...

Rcci Curvature for Metric-Measure Space via Optimal Transport

, M.Sc. Thesis Sharif University of Technology Taheri, Abolfazl (Author) ; Bahraini, Alireza (Supervisor) ; Ranjbar Motlagh, Alireza (Co-Advisor)

Abstract

One of the important questions in mathematics is generalized. In case of metric spaces, one of the questions is: Can we extend notions of Riemannian geometry to arbitrary metric spaces smoothly? Ricci curvature is one of the most important concepts in differential geometry. Ricci curvature is defined for the Riemannian manifold and has many applications in mathematics and physics like Einstein’s equation in relativity theory. There is a good notion for a metric space having “sectional curvature bounded below by K” or “sectional curvature bounded above by K”, due to Alexandrov. Can we define the concept of Ricci curvature in metric space? A motivation for this question comes from Gromov’s...

, M.Sc. Thesis Sharif University of Technology (Author) ; Khaloo, Alireza (Supervisor)

Abstract

Seismic design codes reduce loads by using response modification factor. Because of the reserved strength in structural elements and capacity of structure to dissipate energy, structures can be designed for lower seismic loads. This factor has modified over time. In this thesis, the effect of the reduction in behavior factor on the response of two kinds of reinforced concrete systems were evaluated. Moment resisting frames and dual systems with different heights and regularity in plan, heve been design according to the behavior factor which is recommended in the 3rd edition of the Iranian codes of practice for seismic resistance design of buildings (Standard No. 2800). Drift and...

Prediction of Financial Markets Using Combination of Artificial Intelligence and Technical Analysis

, M.Sc. Thesis Sharif University of Technology (Author) ; Haji, Alireza (Supervisor)

Abstract

Generally, nowadays, machine learning methods are used in many different areas for their superiority over other methods of prediction. Although being a tough task, stock market prediction with machine learning approaches is being spread due to satisfying results published ever yday. Machine learning methods usually use varied kinds of data ,including structured data such as market data, technical indicators and some fundamental data as well as unstructured one entailing text and graph data in order to enhance their predictability capacity. In this thesis we aimed to find out more about the importance and the contribution of structured data in prediction and we tried to attain a framework...

, M.Sc. Thesis Sharif University of Technology (Author) ; Hajji, Alireza (Supervisor)

Abstract

This thesis presents an inventory control system which is based on Meta-heuristic Algorithms.In this thesis we will optimize the input values of our tree-echelon inventory model (keeping costs,stock worth,reorder costs,...) with these Algorithms. The presented method is able to determine the optimal stock level, costs of system and number of shipments in the system. The method is basically a decision support system (DES) and it is able to provide the order scheduling parameters of goods at operational level. The aim of the current research is to demonstrate that a Meta-heuristic algorithmis capable of solving complex inventory problems and with future improvements it is able to achieve...

The Ricci Flow with Applications to the Poincare and Calabi Conjectures

, M.Sc. Thesis Sharif University of Technology Safdari, Mohammad (Author) ; Bahreini, Alireza (Supervisor)

Abstract

Poincare conjecture is one of the rst eorts for classifying 3-manifolds that was stated in the begining of 20th century. Eorts for proving this conjecture continued for about 100 years and nally Perelman has solved it in 2003. He has used Ricci ow which has been invented by Richard Hamilton in the early 80's. In this thesis rst we will introduce Ricci ow and will state the results before Perelman such as short time and long time existence of solution. Then we will mention some applications of Ricci ow and will state an explanation of the proof of uniformization and Calabi conjecture by Ricci ow. After that we start the main part of the thesis. In this part we will montion one of the...

Feasibility And Study(CNG Cylinder Production Plant)

, M.Sc. Thesis Sharif University of Technology Mousavi, Mohammad (Author) ; Haji, Alireza (Supervisor)

Abstract

Nowadays best using of fossil fuels sources of the country (and) importance of comparison against lack of capacity in petrol production make determined the programmers and the directors to foresee and design expanded programs of the goals, to use natural gas for car fuels. To reach fulfillment of these programs, the confirmed needs of the natural gas cylinders are improved and make it essential to invest on producing compressive natural gas cylinders. In this way economical and technical change researches has been done in order to construct on department to produce 200,000 compressive natural gas cylinders in a year during two sets.(shifts) According to the results of technical researches...

Synthesis, Characterization and Field Emission Study of Molybdenum Oxide (MoOx)Nanostructures

, M.Sc. Thesis Sharif University of Technology Khademi, Ali (Author) ; Moshfegh, Alireza (Supervisor)

Abstract

Different molybdenum oxide nano/micro structure thin films were synthesized by thermal evaporation method under various growth conditions such as deposition time, temperature and evaporation source-substrate distance. Molybdenum oxide nanostructures grown on Si(100) such as nanowalls, nanostars and nanowires were characterized with scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), atomic force microscopy (AFM) and high resolution transmission electron microscopy (HRTEM). Shape and type of nanostructures were determined with SEM, AFM and HRTEM analysis. XPS analysis showed that the synthesized nanostructures contained Mo6+, Mo5+, Mo4+ and...

Identification and Abnormal Condition Detection of a Cement Rotary Kiln

, M.Sc. Thesis Sharif University of Technology Sadeghian, Masoud (Author) ; Fatehi, Alireza (Supervisor)

Abstract

One of the most important parts of a cement factory is the cement rotary kiln which plays a key role in quality and quantity of produced cement. In this part, the physical exertion and bilateral movement of air and materials, together with chemical reactions take place. Thus, this system has immensely complex and nonlinear dynamic equations. These equations have not worked out yet. Only in exceptional case; however, a large number of the involved parameters were crossed out and an approximation model was presented instead. This issue caused many problems for designing a cement rotary kiln controller. In this thesis, we employed a nonlinear system identification method for identification,...

Entanglement and Decoherence in Optomechanical Systems Coupled through Photothermal Effects

, Ph.D. Dissertation Sharif University of Technology Abdi, Mehdi (Author) ; Bahrampour, Alireza (Supervisor)

Abstract

Optomechanical systems have attracted considerable attention in the last decade. Such a raising prominence is mainly due to its capability in providing new insight into the quantum behavior of macroscopic objects and exploring the interface between quantum and classical mechanics. Alongside this fundamental quest, cavity optomechanics has many other benefits, ranging from very precise measurements on forces and positions to quantum information processing. In this thesis, we investigate quantum properties of such systems. Particularly, we study cooling of the mechanical resonator toward its ground state and the entanglement between this mechanical resonator and the cavity field. Cooling the...